1. Field of the Invention
The present invention relates to a method of making aqueous dispersions of polymer particles loaded with at least one hydrophobic compound.
By the term "loaded" is meant that said at least one hydrophobic substance is adsorbed on or absorbed by the polymer particles that constitute the dispersed phase.
2. Description of the Prior art
Methods for associating hydrophobic ingredients with polymer particles have been described in i.a. U.S. Pat. Nos. 4,203,716, 4,214,047, 4,247,627, 4,304,769, and GB-A 1,504,949.
Known loaded polymer particles are prepared by adding an aqueous dispersion of polymer particles with stirring to a solution of the hydrophobic compound in a water-miscible solvent or mixture of such solvents. The stability of loaded polymer particles is of great importance, of course. The loaded hydrophobic compound must not desorb or dissociate indeed from the polymer particles. Unfortunately, prior art loaded polymer particles often have a poor stability and may comprise fractions of crystallized hydrophobic compound. Also the loaded polymer particles often tend to form conglomerations.